Get PowerVR working
Using libhybris, it could be possible to get accelerated graphics working by using old vendor kernels with built in PowerVR drivers. Using mainline is a lot more work and for now impossible, but getting accelerated graphics working in a Wayland compositor could possibly be feasible, which I like to discuss in this issue.
This article contains some more information about using Android graphics device drivers with Wayland: http://mer-project.blogspot.com/2013/04/wayland-utilizing-android-gpu-drivers.html
Another possibly interesting issue: https://github.com/libhybris/libhybris/issues/368
People from Leste are working on supporting PowerVR with free drivers, which could also serve as a base for Sunxi and Exynos: https://maemo-leste.github.io/maemo-leste-eight-update-january-february-2019.html
Thread from people who are working on PowerVR with the mainline kernel on a i900: https://github.com/PabloPL/linux/issues/18